ML139326
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Subject 1: (Interview). Subtitle: Tim Stanton. Timecode In: 00:01:27. Timecode out: 00:28:35. Notes: Acoustic scattering properties of live zooplankton. Subject 2: (Sound Effects). Subtitle: Waves. Timecode In: 00:28:37. Timecode out: 01:11:26. Subject 3: (Interview). Subtitle: William Michaels. Timecode In: 01:11:28. Timecode out: 01:24:00. Notes: Predator-prey study on Georges Bank. Subject 4: (Interview). Subtitle: William Michaels. Timecode In: 01:29:23. Timecode out: 01:36:12. Notes: Predator-prey study on Georges Bank. Subject 5: (Environmental Recording). Subtitle: Large boat ambi. Timecode In: 01:36:35. Timecode out: 02:00:22. Habitat: ; Marine Shoreline; ; ; ; ; Equipment Notes: Stereo=1; Decoded MS stereo; Omnis; B&K 4006 Omni mics. Overfishing DAT #3 TS = Tim Stanton BM = Bill Michaels AC = Alex Chadwick inside an interview with Tim Stanton mid left side right setting it up through 00:44 00:45 inside sound -NG through 1:01, then something is strange with the sound -only can hear it clearly through one ear..... 1:26 TS: My name is Tim Stanton. I am senior scientist at the Woods Hole Oceanographic Institution in Woods Hole, Massachusetts ....my project is to measure and characterize the acoustic scattering properties of live zooplankton. 1:48 AC: OK, just show us what's happening here on these small scopes in front of us. 1:55 What we have here is an oscilloscope. An oscilloscope presents us with a display of voltage versus time. And as I said before, we are measuring acoustic echo properties, or acoustic scattering properties of the zooplankton but to do that we need to use voltages, in which we apply voltages to our underwater loudspeakers, or our transducers, the voltage then get translated into sound. that bounces off the animals, and comes back to our receiver, and that transfers the acoustic energy and the voltage and it gets displayed on our voltage vs. time display. So its a somewhat complicated process, but it allows us to do a quantitative study. So what we have here is a squiggly line, and it begins somewhat flat and that's a dead time. that's a little bit like when you clap your hands near the wall. for a while you don't hear anything. and then eventually you hear this echo coming back. and so the first blip, this wiggly blip, is the echo from this ob beat we have suspended in front of our underwater loudspeaker. and following that is another dead zone, and so there is no echo, and then after that we have this much louder echo which is the echo from the back of the tank. and so we have 2 big echoes here. 3:40 AC this actually is ultra sound. we can't actually hear this, although its active and going on right now. TS-That's right. all we can hear right now is just the sound of the fan which keeps our power supply cool. our lowest frequency is 50 khz or 50,000 cycles per second so the mechanical vibrations in the water are going back and forth 50,000 times per second. now the highest pitch that we can here is 20,000 cycles per second. now that's a very high pitch. older people can maybe hear as high as 10,000. when we speak it's usually a few thousand cycles or lower. concert A is 440 cycles per second. so that tells you about some of the ranges that we have. so we are about -our lowest pitch is about 2 and a half times higher than the highest audible sound. 4:41 AC could a dog hear this? 4:44 TS i don't know enough about dogs to be able to answer that, but given that dog whistles are ultra sonic it could possibly be up in that range. This is up in the same range that bats can hear. And our upper range is in the same range as the medical ultra sound. which people use echo scanners, which are scaled down versions of what we are doing to monitor human fetuses. discussion of how to get a clear sound...........ambi of the background... 5:56-6:58 6:59 AC Thing... (Notes truncated)
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Archival information
- Cataloged
- 18 May 2005 - Ben Brotman
- Digitized
- 17 May 2005 - Ben Brotman
- Edited
- 18 May 2005 - Ben Brotman